Spatial engineering of photon-photon entanglement in a quantum dot molecule system

We investigate photon-photon entanglement via the Duan criterion within a three-level closed-loop system embedded in an ensemble of quantum dot molecules (QDMs). In this configuration, one of the interacting quantum modes is treated as a structured quantized field carrying a helical wavefront (Laguerre-Gaussian mode). We demonstrate that the resulting quantum entanglement exhibits a highly non-uniform spatial distribution across the transverse plane of the QDM ensemble. Due to the phase-sensitive nature of the closed-loop system, this spatial profile is strongly modulated by both the magnitude and sign of the orbital angular momentum (OAM) carried by the quantum mode. Our numerical results reveal that the entanglement pattern can be tailored from a uniform circular distribution into discrete multi-lobe structures. This precise spatial engineering of quantized photon entanglement opens up new avenues for high-dimensional quantum cryptography, spatially-multiplexed quantum communications, and the development of solid-state high-capacity quantum memories.We investigate photon-photon entanglement via the Duan criterion within a three-level closed-loop system embedded in an ensemble of quantum dot molecules (QDMs). In this configuration, one of the interacting quantum modes is treated as a structured quantized field carrying a helical wavefront (Laguerre-Gaussian mode). We demonstrate that the resulting quantum entanglement exhibits a highly non-uniform spatial distribution across the transverse plane of the QDM ensemble. Due to the phase-sensitive nature of the closed-loop system, this spatial profile is strongly modulated by both the magnitude and sign of the orbital angular momentum (OAM) carried by the quantum mode. Our numerical results reveal that the entanglement pattern can be tailored from a uniform circular distribution into discrete multi-lobe structures. This precise spatial engineering of quantized photon entanglement opens up new avenues for high-dimensional quantum cryptography, spatially-multiplexed quantum communications, and the development of solid-state high-capacity quantum memories.

Jul 29, 20260 citations

Spatially dependent optical behavior of a quantum dot molecule system

Zahra Amini Sabegh, D.B. Hayrapetyan

We investigate the optical response of a closed-loop three-level quantum dot molecule driven by a structured Laguerre-Gaussian field carrying orbital angular momentum (OAM). Owing to the intrinsic phase sensitivity of the closed-loop configuration, the spatial phase structure of the coupling beam directly imprints on the probe-field dynamics, leading to a strongly spatially dependent optical response. As a result, phenomena such as Autler-Townes splitting, probe absorption, and amplification without inversion arise under both resonant and off-resonant conditions, with their spectral characteristics governed by the sign and magnitude of the OAM index. This OAM-controlled modulation of the optical response reveals a mechanism for phase-engineered light-matter interaction in quantum dot molecules. The results highlight the potential of this solid-state platform for structured light based quantum photonics, including quantum information processing, tunable slow and fast light, and high capacity optical data storage.We investigate the optical response of a closed-loop three-level quantum dot molecule driven by a structured Laguerre-Gaussian field carrying orbital angular momentum (OAM). Owing to the intrinsic phase sensitivity of the closed-loop configuration, the spatial phase structure of the coupling beam directly imprints on the probe-field dynamics, leading to a strongly spatially dependent optical response. As a result, phenomena such as Autler-Townes splitting, probe absorption, and amplification without inversion arise under both resonant and off-resonant conditions, with their spectral characteristics governed by the sign and magnitude of the OAM index. This OAM-controlled modulation of the optical response reveals a mechanism for phase-engineered light-matter interaction in quantum dot molecules. The results highlight the potential of this solid-state platform for structured light based quantum photonics, including quantum information processing, tunable slow and fast light, and high capacity optical data storage.

Scientific ReportsJul 10, 20260 citations

Spatial-dependent quantum dot-photon entanglement via tunneling effect

Yaser Delir ghaleh joughi, Mostafa Sahrai

Utilizing the vortex beams, we investigate the entanglement between the triple-quantum dot molecule and its spontaneous emission field. We present the spatially dependent quantum dot-photon entanglement created by Laguerre-Gaussian (LG) fields. The degree of position-dependent entanglement (DEM) is controlled by the angular momentum of the LG light and the quantum tunneling effect created by the gate voltage. Various spatial-dependent entanglement distribution is reached just by the magnitude and the sign of the orbital angular momentum (OAM) of the optical vortex beam.Utilizing the vortex beams, we investigate the entanglement between the triple-quantum dot molecule and its spontaneous emission field. We present the spatially dependent quantum dot-photon entanglement created by Laguerre-Gaussian (LG) fields. The degree of position-dependent entanglement (DEM) is controlled by the angular momentum of the LG light and the quantum tunneling effect created by the gate voltage. Various spatial-dependent entanglement distribution is reached just by the magnitude and the sign of the orbital angular momentum (OAM) of the optical vortex beam.

Scientific ReportsMay 14, 20228 citations

Spatially dependent atom-photon entanglement

Zahra Amini Sabegh, Rahim Amiri, Mohammad Mahmoudi

The atom-photon entanglement using the Laguerre-Gaussian (LG) beams is studied in the closed-loop three-level V-type quantum systems. We consider two schemes with near-degenerate and non-degenerate upper levels: in the first, the effect of the quantum interference due to the spontaneous emission is taken into account and in the second, a microwave plane wave is applied to the upper levels transition. It is shown that the atom-photon entanglement in both schemes depends on the intensity profile as well as the orbital angular momentum (OAM) of the applied fields so that the various spatially dependent entanglement patterns can be generated by Laguerre-Gaussian beams with different OAMs. However, due to the zero intensity,no entanglement appears in the center of the optical vortex beams. As a result, the entanglement between dressed atom and its spontaneous emissions in different points of the atomic vapor cell can be controlled by the OAM of the applied fields. Moreover, our numerical results show that the number of the local maximum degree of entanglement (DEM) peaks depends on the OAM of the applied fields. The degrees of freedom for OAM play a crucial role in spatially dependent atom-photon entanglement in such a way that it may possess broad applications in high-dimensional quantum information processing and data storage.The atom-photon entanglement using the Laguerre-Gaussian (LG) beams is studied in the closed-loop three-level V-type quantum systems. We consider two schemes with near-degenerate and non-degenerate upper levels: in the first, the effect of the quantum interference due to the spontaneous emission is taken into account and in the second, a microwave plane wave is applied to the upper levels transition. It is shown that the atom-photon entanglement in both schemes depends on the intensity profile as well as the orbital angular momentum (OAM) of the applied fields so that the various spatially dependent entanglement patterns can be generated by Laguerre-Gaussian beams with different OAMs. However, due to the zero intensity,no entanglement appears in the center of the optical vortex beams. As a result, the entanglement between dressed atom and its spontaneous emissions in different points of the atomic vapor cell can be controlled by the OAM of the applied fields. Moreover, our numerical results show that the number of the local maximum degree of entanglement (DEM) peaks depends on the OAM of the applied fields. The degrees of freedom for OAM play a crucial role in spatially dependent atom-photon entanglement in such a way that it may possess broad applications in high-dimensional quantum information processing and data storage.

arXiv:1803.02048Scientific ReportsSep 10, 201821 citations

High-dimensional maximally entangled photon pairs in parametric down-conversion

Richard Bernecker, Baghdasar Baghdasaryan, S. Fritzsche

Photon pairs generated from spontaneous parametric down-conversion are a well-established method to realize entangled bipartite photonic systems. Laguerre-Gaussian modes, which carry orbital angular momentum (OAM), are commonly exploited to engineer high-dimensional entangled quantum states. For Hilbert spaces with dimension $d>2$ , maximally entangled states (MESs) help to improve the capacity and security of quantum communication protocols, among several other promising features. However, the direct generation of MESs in well-defined high-dimensional subspaces of the infinite OAM basis has remained a challenge. Here, we formalize how the spatial distribution of the pump beam and the nonlinear profile of the crystal can be simultaneously utilized to generate MESs without additional spatial filtering of OAM modes within a subspace. We illustrate our approach with maximally entangled qutrits $(d=3)$ and ququints $(d=5)$ .Photon pairs generated from spontaneous parametric down-conversion are a well-established method to realize entangled bipartite photonic systems. Laguerre-Gaussian modes, which carry orbital angular momentum (OAM), are commonly exploited to engineer high-dimensional entangled quantum states. For Hilbert spaces with dimension $d>2$, maximally entangled states (MESs) help to improve the capacity and security of quantum communication protocols, among several other promising features. However, the direct generation of MESs in well-defined high-dimensional subspaces of the infinite OAM basis has remained a challenge. Here, we formalize how the spatial distribution of the pump beam and the nonlinear profile of the crystal can be simultaneously utilized to generate MESs without additional spatial filtering of OAM modes within a subspace. We illustrate our approach with maximally entangled qutrits $(d=3)$ and ququints $(d=5)$.

arXiv:2407.09280Physical Review ASep 26, 20246 citations

Entanglement of photons with complex spatial structure in Hermite-Laguerre-Gaussian modes

Jie Ying Tang, Yang Ming, Zhaoxian Chen +3 more

Photons with complicated spatial mode structures can be applied for different quantum information tasks. Here, we show the entanglement of photons with complex singularity patterns called Hermite-Laguerre-Gaussian (HLG) modes. Measuring one photon of the entangled pairs by HLG mode basis to define its singularity pattern, we can steer the singularity structure of its partner, while the initial singularity structure of the photons is undefined. We also calculate the HLG specific quantum-correlation function. It can be used to extend the quantum key distribution protocols and to tune experiments dealing with high-order transverse modes. In addition we discuss orbital angular momentum properties of the HLG modes and summarize some features of the singularity pattern of the HLG modes with varying angle parameter.Photons with complicated spatial mode structures can be applied for different quantum information tasks. Here, we show the entanglement of photons with complex singularity patterns called Hermite-Laguerre-Gaussian (HLG) modes. Measuring one photon of the entangled pairs by HLG mode basis to define its singularity pattern, we can steer the singularity structure of its partner, while the initial singularity structure of the photons is undefined. We also calculate the HLG specific quantum-correlation function. It can be used to extend the quantum key distribution protocols and to tune experiments dealing with high-order transverse modes. In addition we discuss orbital angular momentum properties of the HLG modes and summarize some features of the singularity pattern of the HLG modes with varying angle parameter.

Physical Review AJul 7, 201626 citations

d>2

, maximally entangled states (MESs) help to improve the capacity and security of quantum communication protocols, among several other promising features. However, the direct generation of MESs in well-defined high-dimensional subspaces of the infinite OAM basis has remained a challenge. Here, we formalize how the spatial distribution of the pump beam and the nonlinear profile of the crystal can be simultaneously utilized to generate MESs without additional spatial filtering of OAM modes within a subspace. We illustrate our approach with maximally entangled qutrits

(d=3)

and ququints

(d=5)